Fillet Weld Size
Fillet welds are used for many applications and are important for the strength of the joint. Fillet weld size is usually specified on the drawing. Understanding the fillet weld symbols and their meaning is important for producing strong and reliable joints.
Fillet welds are stronger than spot welds and are generally used for permanent, static, or static/dynamic applications. The strength of a joint depends on the force or load applied, the type of material, and the size and shape of the weld.
There are several types of fillet welds, including butt, corner, lap, and tee joints. The size of each joint depends on the forces or loads applied and the type of material used. The size of the weld is also affected by the thickness of the material and the application.
Fillet weld symbols can be found on the drawing or on the weld joint. Common symbols are used to identify the size and shape of the weld, the type of weld, the material, the position of the weld, the procedure number, and the welding process.
When reading the drawing, it is important to remember that fillet weld size is usually indicated as a number. The number corresponds to the nominalsizediameteroftheweld.Nominationalsizeisdetermined by taking the average of the minimum and maximum size of the weld.
Referring to the chart below, a fillet weld size of 75 indicates that the diameter of the weld is 0.75inch.The number in the chart below provides an inside measurement of the weld size.
Fillet Weld Size Chart
Nominal Size (inch) Inside Measurement of Weld (inch)
1/16 0.0625
3/32 0.0938
1/8 0.125
5/32 0.1563
3/16 0.1875
7/32 0.2188
1/4 0.25
5/16 0.3125
3/8 0.375
7/16 0.4375
1/2 0.5
5/8 0.625
3/4 0.75
7/8 0.875
1 1
1 1/4 1.25
1 1/2 1.5
2 2
When reading the drawing, it is important to remember that the number stated may not be the actual size of the weld. The actual size of the weld is determined by measuring the inside measurement of the weld, as indicated in the chart above. The size stated on the drawing is generally a nominal size.
It is also important not to mistake the fillet weld size with the depth, or leg length, of the fillet weld. The depth or leg length of the weld is typically determined by the thickness of the material.
The size of a weld is important when using prequalified welding procedures or when welding structural steels, pressure vessels, or pipelines. The size of the weld must be large enough to produce adequate strength of the joint.
Understanding the fillet weld symbols and their meanings is important when producing a reliable and strong joint. Using the fillet weld size chart, the relationship between the number stated on the drawing and the actual size of the weld can be determined.
